Basic Electrical and Electronics Engineering by S. K. Bhattacharya | 9788131798690 | 8131798690

Electronics and Electrical

Basic Electrical and Electronics Engineering

228 SOLVED PROBLEMS

5 SOLVED PROBLEMS

Question: II.B.3

(a) Derive the expression for resonant frequency and Q factor for a series resonant R–L–C circuit. (b) A coil of resistance 15 ohms and inductance 0.05 H is connected in parallel with a non-inductive resistor of 20 ohms. Find: (i) The current in each branch and the total current supplied.(ii) The ...

Verified Answer:

(a) An ac circuit is said to be resonant when: • T...

Question: II.B.2

(a) An aluminium wire with a diameter of 2 mm and length of 10 m wire is connected in parallel to a copper wire 6 m long. A total current of 2 A is passed through the combination and it is seen hat the current through the aluminium wire is 1.25 A. Calculate the diameter of the copper wire. The . ...

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(a) Total current, I = 2 A AL Current through alum...

Question: III.B.4

(a) Explain the phenomenon of resonance in an L–R–C series circuit. (b) A circuit of R =4 Ω , L =0.5 H and a variable capacitor C in series is connected across a 100 V, 50 Hz supply. Calculate (i) the value of the capacitor for which resonance will occur; (ii) voltage across the capacitor at ...

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(a) Resonance in L–R–C series circuit: In the seri...

Question: III.B.3

(a) Derive an expression for the EMF equation of a dc generator. (b) The applied voltage and current fl owing through in an L–R circuit are v =200 sin (314+π/3) and I= 20 sin(314+π/6) Calculate the (i) power factor, (ii) average power, (iii) impedance, and (iv) values of R and L ...

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(a) EMF equation of a dc generator: Figure 45 show...

Question: III.B.2

(a) Find the value of R and the current through each branch in the circuit shown in Fig. 39 if the current in branch AO is zero. (b) Calculate the current flowing through the 6 Ω resistor in the circuit shown in Fig. 40 ...

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(a) The circuit is redrawn as shown in Fig. 42. Si...

Question: III.j

Three resistances R, 2R and 3R are connected in delta. Determine the resistances for an equivalent star connection. ...

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R_{A}=\frac{R×2R}{R+2R+3R}=\frac{2R²}{6R}=\...

Question: III.i

Convert the decimal number 0.8125 into its equivalent binary number. ...

Verified Answer:

(0.8125)_{10} =(?)_{2}

Fractio...

Question: III.h

A coil of resistance 3.14 Ω and inductance 0.01 H is connected to a supply of 12 V, 50 Hz. Calculate the current through the coil. ...

Verified Answer:

R = 3.14 Ω L = 0.01 H

X_{L}=\omega L [/late...

Question: III.g

Draw the symbols of BJT and zener diode. ...

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The symbols of BJT and zener diode are shown in Fi...

Question: III.f

State the laws of electromagnetic induction ...

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Faraday showed that electricity could be produced ...

Question: 16.2

Binary number is 11010. Convert this number into its decimal equivalent. ...

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\begin{array}{llllll} 1 & 1 & 0 &am...

Question: 15.1

A half-wave diode rectifier has a forward voltage drop, i.e., voltage drop across the diode when conducting is 0.7 V. The load resistance is 600 Ω. The rms value of the ac input is 28.87 V. Calculate Idc, Irms, PIV, and form factor. ...

Verified Answer:

\begin{aligned} & \mathrm{V}_{\mathrm{i...

Question: 3.41

An inductive coil of resistance 5 Ω and inductive reactance 10 Ω is connected across a voltage of 230 V at 50 Hz. Calculate the value of the capacitor which when connected in parallel with the coil will bring down the magnitude of the circuit current to a minimum. Draw the phasor diagram. ...

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Before a capacitor is connected, current flowing t...

Question: 3.37

An inductive coil of resistance 10 Ω and inductance 20 mH are connected in series with a capacitor of 10 μF. Calculate the frequency at which the circuit will resonate. If a voltage of 50 V at resonant frequency was applied across the circuit, calculate the voltage across the circuit components and ...

Verified Answer:

\mathrm{R}=10 \Omega, \mathrm{L}=20 \times ...

Question: 3.36

An inductor, a variable capacitor, and a resistor are connected in series across a constant voltage, 100 Hz power supply. When the capacitor value is fixed at 100 μF, the current reaches its maximum value. Current gets reduced to half its maximum value when the capacitor value is 200 μF. Calculate ...

Verified Answer:

Let resonant frequency be

f_0

. [lat...